The study examined the relationship between financial management practices and the business sustainability of manufacturing firms in Nakawa Division, Kampala. The study was motivated by the increasing closure rates of manufacturing enterprises in the division and the attribution of these closures to financial management deficiencies. A cross-sectional research design was employed, with data collected from 155 respondents representing 52 manufacturing firms. The study focused on three financial management practice dimensions: financial reporting and accountability, budgetary control, and cash flow management. Findings revealed that cash flow management (β=0.367, p<0.001), budgetary control (β=0.298, p<0.001), and financial reporting and accountability (β=0.241, p<0.01) were all significant positive predictors of business sustainability. The regression model accounted for 61.2% of the variance in business sustainability. The study concluded that improving financial management practices was critical for enhancing the sustainability of manufacturing firms in Nakawa Division and made specific recommendations for firm management and policy intervention.